A Radio Frequency (RF) transmitter has to fulfill a certain frequency band-dependent output power spectrum mask according to a communication standard (e.g. defined by the 3rd Generation Partnership Project, 3GPP). A polar transmitter commonly has a higher efficiency than a conventional I/Q transmitter. However, for a polar transmitter, the time quantization (of the zero crossing) determines mainly the out-of-band noise of the output RF signal. A large time quantization may be easy to achieve technically but leads to large out-of-band noise. A small time quantization may be achieved with sophisticated (and thus heavily current consuming) Digital-to-Time Converter (DTC) circuits and lead to small out-of-band noise. Additionally, for a periodic input to the polar transmitter, a periodic time quantization causes spurious signal components in the output RF signal due to periodic pattern.
Hence, there may be a desire for an improved transmitter architecture.